[Biology Class Notes] on Lysosomes Pdf for EXAM

Lysosomes are sphere-shaped cell organelle that is found within the eukaryotic animal cells and has the capability of breaking down many types of biomolecules. They are also being called the suicidal bags of the cell. The term lysosomes were derived by Christian de Duve who was a Belgian biologist, who even got a Nobel prize in medicine or physiology in 1974. The specific function of the lysosomes is breaking down the cellular wastes and debris which is done by engulfing them with hydrolytic enzymes.

Structure of Lysosomes

Lysosomes are the organelles whose membrane is bounded by a membrane the area which is within the membrane is known as the lumen and it contains hydrolytic enzymes and other cellular debris. The pH level of the lumen always lies between 4.5 and 2.0, which helps in making it quite acidic. It can be compared with the functions of acids that are found within the stomach. The size of every lysosome varies with each other. Lysosomes are there in various cellular processes like energy metabolism, counting discharged materials, restoration of the plasma membrane, cell signaling, and many more. 

Functioning of Lysosomes

One of the most important functions of Lysosomes is the removal of waste and digestion. Through the process of endocytosis, the foreign particles are being pulled into the cells. The cell membrane falls in on itself and creates a pouch around the external contents, and lastly brings those contents into the cell, then the process of endocytosis happens. On the other hand, the discarded wastes and other substances which originate from within the cell are being digested by the process named autophagy whose other name is autophagocytosis. In this process, degradation or disassembly of the cellular components involves a natural and regulated mechanism. 

Lysosomal Disease

Nuclear genes organize the production of enzymes in the lysosomes. Nuclear genes are those genes that are being located within the nucleus of a cell, especially in eukaryotes. If there are any mutations in these genes, it will result in the emergence of a lot of human genetic ailments which are collectively called LSD (lysosomal storage diseases). 

Lysosomes as the Therapeutic Targets

There are a lot of lysosomal pathways and their components that can represent the potential pharmacological targets for a huge number of diseases. When we consider lysosomes as the targets, it is very important to note down the need for specificity, i.eThe agents will not target all lysosomes, but they will especially target those lysosomes which are defective in a few organs, cells, or tissues. For several reasons, it is very important to target lysosomes and not to target the whole autophagy process. Firstly, regarding safety, the important role of lysosomes in many key physiological processes means that the therapeutic windows for the intervention of pharmacology with unacceptable side effects may be limited.

Summary of Lysosomes

• Lysosomes are cell organelles almost exclusively found in eukaryotic animal cells

• Lysosomes are membrane-bound spherical sacs crammed with hydrolytic enzymes

• These enzymes can break down many sorts of biomolecules like proteins and fats

• Lysosomes are known as the ‘Suicidal Bags’ as they have the capacity to destroy the cell wall with its digestive enzymes, causing autolysis of the cell

• Lysosomal enzymes are synthesized within the rough endoplasmic reticulum, where they’ve brought in by the Golgi body through tiny vesicles. It eventually merges with bigger acidic vesicles

• Mutations of the nuclear gene may end in the emergence of rare, diverse human genetic ailments, which are called lysosomal storage diseases or LSD